Process of manufacturing inner elastic air-tubes for pneumatic tires



(No Model.) 2 Shets-8heet 1.

P. w. MORGAN. I PROCESS OF MANUFACTURING INNER ELASTIC AIR TUBES FOR- PNEUMATIG TIRES.

No. 544,627. Patented Aug. 13,1895.

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- 2 Sheets -Sheet 2. F. W. MORGAN, PROCESS OF MANUFACTURING INNERELASTIG AIR TUBES FOR PNEUMATIC TIRES. No. 544,627; PatentedAug. 13, 1895.

(No Model.)

' NI'IED" STATES FRED W. MORGAN, OF CHICAGO, ILLINOIS.

PATENT OFFICE.

PROCESS QF MANUFACTURING INNER ELASTIC AIR-TUBES FOR PNEUMATIC TIRES. I

SPECIFICATION forming part of Letters Patent No. 54 4,627, dated August 13, 1895. Application filed May 9, 1895. Serial No. 548,672. (No model.)

To all whom it may concern:

Be it known that I, FRED W. MORGAN, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illi-' nois, have invented a certain new and useful Improvement in the Process of Manufacturing Inner Elastic Air-Tubes for Pneumatic Tires, of which the following is a specification.

vulcanized rubber-stock into long sheets or In carrying 'out my invention I form unstrips of thin film by passing the stock through suitable calender-rolls, it being understood that the film thus produced can be separated into sheets or long sheets or strips of suitable width, either during or subsequent to its formation. 1 then spread upon an elastic bed or cushion-table several sheets of this unvulcanized rubber-film, the width of each sheet being a little greater than the circumference of the proposed inner elastic multiply air-tube which is to be constructed, so that each sheet of film can lap upon itself to a suitable extent when rolled into tubular form. The length of each of these sheets of film is equal to the length of the tube which is to be formed by rolling the sheets about a long cylindric rod or mandrel, and the said sheets are arranged side by side upon the flat yielding surface of the cushion-table, so that they can be successively rolled about the mandrel and pressed down, so as to compress the film between the mandrel and the cushion-table, and thereby exclude air-bubbles from be tween the sheets or plies of film, it being observed that if air-bubbles are left between such plies the tube will be imperfect. After the sheets or plies of film have been rolled up about the mandrel and directly upon one another the multiply tube thus formed is vulcanized, so as to unite the plies as one piece. These plies of film can be made of uniform grade and thickness, or they can be severally made of different kinds of stock or of different thickness, or both, as may be desired. The plies are also preferably so arranged upon the cushion-table preparatory to rolling them up as to bring the laps at different points around the tube, thereby avoiding undesirable thickness at any one point, it being obmatic tires, the aggregate thickness of the several plies of film not only need not exceed but can be less than the thickness of the material of an inner tube formed by a single sheet of rubber, and by employing several sheets of film the tube can be made more perfect, since if an imperfection occurs in one sheet of film it will as a rule'be covered by a perfect portion of the next adjacent sheet of film, while, on the other hand, if the tube is formed by a single sheet of rubber, an iuiperfectionsuch as a small portion of foreign vegetable matter (com'moh in rubber) or a minute air-bubble will usually result in the formation of a blister in the tube during vulcanization, and thereby render the tube imperfect. I prefer that the ultimate thickness of the tube shall be about three sixty-fourths of an inch thick, although it can be made slightly thinner or slightly thicker. If the plies of film are of equal thickness and the thickness of the tube is to be three sixty-fourths of an inch, each ply of film will of course be one sixty-fourth of an inch thick. For some purposes, how- I in number as to produce a multiply tube of. the same thickness as it would have it composed of plies of equal relative thickness. The vulcanization of this multiply tube IQO.

serves to unite the plies as one piece, and by.

arranging the plies so that the laps will be out of. register with one another no undulythickened portions will occur, owing to the fact that each lap will only involve the additional thickness of one edge portion of a thin sheet of film, and to the further fact that such slightly-thickened portions, caused by the several laps of the several sheets of film,are distributed at different points in the air-tube. The rubber film is delicate, sticky, flimsy,and hard to handle, but by unrolling it from one or more spools, spreading it in sheets at differ ent points upon a cushion-table, and then successively rolling it about a rod or mandrel it can be manipulated with ease and rapidity, and each ply can be rolled up smoothly and evenly by one operation extended sufficiently to permit the plies to be successively rolled up.

In the accompanying drawings, Figure 1 represents in top plan a series of such pieces of unvulcanized rubber film arrangedup'on an elastic bed or cushion-table. Fig. 2 shows the same in side elevation with one of the pieces rolled about the mandrel. Fig. 3 is a like view showing two of the pieces completely rolled about the mandrel and the third partially rolled up. Fig. 4 shows in crosssection the multiply tube on the mandrel. Fig. 5 shows the tube in longitudinal section removed from the mandrel and having its ends flattened down and closed. Fig. 6. illustrates the end edges of three plies of film of different relative thicknessthe surface of the, cushion-table being indicated by a single line.

The cushion-table A can be formed by any suitable yielding and elastic material, asimple and efiicient construction being to. form the cushion portion of felt havinga covering of cloth. The film is made of unvulcanized rubber, and to such end the rubber-stock is passed through suitable calenderrolls. A convenient Way of supplying the rubberfilni to the cushion-table is to form the film in strips of the required width and of indefinite.

length and to roll up such strips on spools B, with a layer of cloth between the convolutions. These spools can be arranged at one:

end of the cushion-table, so that preparatory to forming an air-tube asuitable strip or long narrow sheet C of film can be unwound, laid upon the table, and severed from the remaining portion of the strip, the cloth being of course removed from the strips or sheets of film preparatory to rolling them out. The strips or sheets 0 of film are each proportional in length to thelength of the proposed tube which is to be formed by rolling them about the mandrel, and each strip or sheet 0, of film is also desirably of a widthto permit its longitudinal edge portions to lap, when it is rolled into tubular form. The sheets Oof film, which form the plies ofthe multiply tube, are conveniently arranged side by side and at such distances apart that when they are severally rolled up to. formthe multiply.

tube the laps will be along separate lines i having their relative distances apart deter mined by the spaces between the sheets as arranged upon the cushion-table. In this way I can avoid having the laps in register with one another, and thereby avoid unduly thickening the tube at any one point. \Vhere the sheets of film are of different kinds of stock or of difierent relative thickness, or both, it would be possible, by extremely careful handling, to lay the longitudinal edge portion of one sheet of film upon the longitudinal edge portion of the next adjacent sheet of film; but such method will be less desirable, owing to the fact if the second sheet is not properly laid in the first instance its rearrangement will be diffic'ult,owing to the tendency of the sheets of film to adhere when brought into contact with one another, although by such arrangement the laps could be made to occur. along different lines in the completed multiply tube. The several plies or sheets of. film are then successively rolled 1. about a rod or mandrel D and in direct con- 1 tact with one another, and while being thus rolled up. the mandrel is suitably depressed,

j between the mandrel and the cushion-table, E and thereby roll the plies smoothly and evenly f' and exclude airfrolm between them. While do not confine myself to manually rolling the. mandrel over. the cushion-table and sheets of film thereon, I prefer such mode, owing to the ease and rapidity involved, and the furtherfact that the rolling up of the film can be. governed by'the workmen. The multiply tube. thus formed about the mandrel is then vulcanized, so as to unite the plies as one piece and adapt the tube for service in a pneumatic tiresheath, it being understood that the ends of the tube can be closed in any known or suitable way, or: that they can be telescoped, as may be desired. The tube can be vulcanized upon the mandrel, or it 1 can be. removed therefrom and then Vulcan iied, the latter beingfthe. mostdesirable and expeditious mode of procedure The plies j or sheets of film are each arranged upon the up into tubular form about; the mandrel and upon one another. The workmen could first placeone sheet of film upon the cushion-table and roll it up, and then place another. sheet of film upon the cushion-table and roll it up 5 about the sheet of film already rolled about i the mandrel, in which case, however, it will be seen that the operation" would involve spreading. the sheets of film upon the table preparatory to rolling. them up into tubular form, and also involve; successively rolling up. a plurality of such sheets; but as a more economical andbetter. mode and matterof further improvement. all of the sheets of film intended .to be used in any one tube can in the first instancebe properly arranged upon the cushiontable and then rolled up by one operation of the mandrel. With further reference to certain. advanl tages secured by rolling up sheets or plies of film of difierent. kinds or grades of stock or QcushiOn-tabIe preparatory to rolling them of difierent relative thickness, or of both dif- I ferent relative thickness and difierent kindsforming and rolling up the plies as hereinbe fore set forth, one ply can be arranged sothat the grain or fiber of the rubber will lie transverse to the grain or fiber of the next adjacent ply or plies, it being observed that in producing these plies by running the rubber-stock between calender-rolls the grain or fiber of the rubber will run longitudinally along'the strip or ply thus produced, and hence certain of the plies be so cut from a wide sheet of film as to permit the fiber of the rubber therein to run transverse to the fiber of the rubber in the next adjacent ply, by which arrangement a tube less liable to puncture or rupture can be produced. I i

Wh'at'I claim as my invention is v The within described process of preparing elastic, inflatable inner air-tubes for pneumatic tires, consisting essentially in the following steps, to witz- -fo'rming unvulcanized rubber stock into sheets of thin film; spreading a' plurality of such sheets of film preparatory torolling them into tubular form; successively rolling up a plurality of such sheets directly upon one another so as to form a multiply tube, composed of plies of 'unvulcanized rubber film in direct contact with one another, and during such operation subjecting the plies of film to compression; and vulcanizing the multiply tube thus formed so as to unite the plies as one piece and adapt the tube for service in a pneumatic tire sheath.

FRED w. MORGAN.

WVitn esses:

RETA M. WAGNER, ARTHUR H, DURAND. 

